Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
156 views
in Technique[技术] by (71.8m points)

c# - Why Sql Server Image In Binary Causes Issue in string Query but works in Parameterized Query

I am saving Image in a table in VarBinary and its working.but the problem is if i save image using string query when i retrieve it it says parameter not valid although Image binary is save in database and i can see it. but if i use parametrized query and retrieve image it is displayed correctly:

Here is my parametrized query code:

     try
                    {
                        byte[] byteImg = ImageToByteArray(pictureBox1.Image);
                        connection = con.getConnection();
                        if (connection != null)
                        {
                            query = @"INSERT INTO [tblImages]
                               ([Image])
                         VALUES
                               (@image)";
                            connection.Open();
                            cmd = new SqlCommand(query, connection);
                            cmd.Parameters.AddWithValue("@image", byteImg);
                            cmd.ExecuteNonQuery();
                            MessageBox.Show("Saved");
                            connection.Close();
                            pictureBox1.Image = null;
                        }
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.Message);
                    }

Database Row View Using Parameterized:

enter image description here

Here is my string query code:

 try
                {
                     byte[] byteImg = ImageToByteArray(pictureBox1.Image);
                    connection = con.getConnection();
                    if (connection != null)
                    {
                        query = @"INSERT INTO [tblImages]
                           ([Image])
                     VALUES
                           (Convert(varbinary(MAX),'" + byteImg + "'))";
                        connection.Open();
                        cmd = new SqlCommand(query, connection);
                        cmd.ExecuteNonQuery();
                        MessageBox.Show("Saved");
                        connection.Close();
                        pictureBox1.Image = null;
                    }
                }
                catch
                {

                }

Byte Conversion Method:

public byte[] ImageToByteArray(Image img)       
        {
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            return ms.ToArray();
        }

Database Row View:

enter image description here

Why is this happening why using Parametrized query binary is different in row and using string query it different, its very weird.

Any help will be appreciated.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can actually just do:

INSERT INTO [tblImages]  ([Image])
VALUES 0x5379......

To build the binary string use code like this (buffer is your byte array)

_sbScript.Append("0x");

for (int i = 0; i < buffer.Length; i++)
{
    _sbScript.Append(buffer[i].ToString("X2",System.Globalization.CultureInfo.InvariantCulture));
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...